These DC animated movies just can't stop messing with the timestream .In JSWWII, when "Shakespeare" finds the blonde teen boy in the prison cell and the boy insists on giving him his satchel. That is Kamandi giving him the Superman suit he won in this short. Which is what he dons at the end of the movie. Implicitly, Dr. Fate also brought Kamandi to his Earth like Flash to change the timeline.